Recursion in C Programming

In this tutorial, we will study what is recursion in c programming, the structure of the recursion function, the advantages and disadvantages of recursion in c, the types of recursion, and the factorial of a number using recursion.

Recursion in C Programming

Recursion is a process in which the function calls itself. Recursion is used to solve a problem by dividing it into small parts. Such functions which call themselves are called recursive functions.

Structure of Recursive Function

return type myFunction(Parameters-list)
{
  statement 1;
  statement 2; 
  …
  statement N;
  myFunction(Arguments-list);
  …
  other statements;
}

Advantages and Disadvantages of Recursion in c

Advantages

If we solve a problem through Recursion, then there is no need to call the function again and again. If we call the function 1 time, it keeps calling itself till the end result comes.
The same problem is easily solved in recursion.

Disadvantages

Recursive programs are slower than normal programs.
Requires consuming extra memory.

Types of Recursion in C

Direct Recursion

Direct recursion is a recursion in which a function calls itself.

return_type MyFunction(parameter-list)
{
  statements;
  MyFunction(argument-list);
  other statements;
}

Indirect Recursion

In this, one function calls another function which in return calls it itself.

First Function

return_type FunctionOne(parameter-list)
{
statements;
FunctionTwo(argument-list);
other statements;
}

Second Function

return_type FunctionTwo(parameter-list)
{
statements;
FunctionOne(argument-list);
other statements;
}

Factorial of a Number Using Recursion

#include <stdio.h>
#include <conio.h>
long int fact(int n);
int main()
{
  int n;
  printf("Enter a positive integer: ");
  scanf("%d", &n);
  printf("Factorial of %d = %ld", n, fact(n));
  return 0;
}
long int fact(int n)
{
  if (n >= 1)
  return n*fact(n-1);
  else
  return 1;
}

Output

Enter a positive integer: 4
Factorial of 4 = 24

Originally posted on alimammiya.hashnode.dev